Elastomeric pressure-sensitive adhesive compositions exhibiting good cutting performance

ABSTRACT

The cuttability of elastomeric pressure-sensitive adhesives, particularly of hot-melt tackified mutually immiscible elastomers, is improved by the addition of surfactants containing polyethylene-oxide and polypropylene-oxide blocks.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of application Ser. No. 07/802,881 filedDec. 6, 1991 abandoned, which is a continuation-in-part of applicationSer. No. 07/493,365 filed Mar. 14, 1990 of which application Ser. No.07/921,444 filed Jul. 27, 1992 is a continuation.

FIELD OF THE INVENTION

The present invention is directed to elastomeric rubber basedpressure-sensitive adhesive compositions used in label and tapemanufacture where the adhesive employed has improved cuttability andtherefore convertability.

BACKGROUND OF THE INVENTION

During the process of converting pressure-sensitive bulk products suchas rolls of a laminate of a face stock or backing, a pressure-sensitiveadhesive layer, and a release liner into end products, many cuttingoperations are performed. These include slitting, sheeting, guillotiningincluding hole punching and perforating, and die cutting on rotary andflat-bed machines.

Die cutting for label manufacture is the most complex. There, a laminateof a face stock or backing, pressure-sensitive adhesive layer and arelease liner is passed through apparatus which converts the laminate toyield commercially useful labels from label stock. The processesinvolved in converting operations include printing, die cutting andmatrix stripping to leave labels on a release liner, butt cutting oflabels to the release liner, marginal hole punching, perforating, fanfolding, guillotining and the like.

Die and butt cutting involve cutting of the laminate to the face of therelease liner. Other procedures involve cutting clean through the labellaminate and include hole punching, perforating and guillotining.

The cost of converting a laminate into a finished product is a functionof the speed at which the various processing operations occur. While thenature of all layers of the laminate can impact cost of convertability,the adhesive layer has been the greatest limiting factor in ease andcost of convertability. This is in consequence of its viscoelasticnature which hampers precise and clean penetration of a die in diecutting operations and promotes adherence of the adhesive to cuttingblades and the like in converting operations.

For slitting and sheeting, the cutting blade, because of adhesiveadherence, becomes tacky and forms so called "gum balls." The gum ballstransfer to the surface of paper and produce product defects. Quiteoften, the operators have to stop the cutting operation and clean theblade. Placing a lubricant such as mineral oil on the surface of theblade can help the cutting process.

For die cutting, poor cutting causes matrix breaks when waste matrix ispeeled off. In order to avoid the matrix breaks, the press operators areforced to lower the converting speed.

For guillotining where stacks of sheets are cut at the same time, thecutting edge of the paper tends to become tacky. As a result theseparation of each sheet becomes difficult and subsequent printingprocess may be jammed.

In order to improve the converting process, minimization of adhesiveadherence to cutting blades is most important. PG,4

U.S. Pat. Nos. 4,151,319 to Sackoff et. al and 4,346,189 to Laurentclaim addition of silicone oil and gums to adhesive compositions. Theseadditives improve cutting performance, but at a sacrifice in adhesion.

While not directly related to cutting performance, U.S. Pat. No.4,693,935 to Mazurek discloses polysiloxane-grafted adhesive copolymers.The adhesive compositions claimed are repositionable withadhesive-bonding building upon dwell for an extended time.

U.S. Pat. No. 4,548,845 to Parsons et. al teaches the addition of apolyoxyalkylene polyol such as polyethylene glycol to tackifiedwater-insoluble adhesives to reduce the adhesive build-up on a knifeblade during guillotine cutting. This has resulted in phase separationand incompatibility in some adhesive systems.

SUMMARY OF THE INVENTION

According to the invention, cutting performance of pressure-sensitiveadhesive compositions is improved by the addition of block copolymerswith hydrophilic and hydrophobic blocks with the following structuresbeing preferred:

    PEO--PPO--PEO                                              (1)

    PPO--PEO--PPO                                              (2)

    (PEO--PPO--).sub.4 (3)

    (PPO--PEO--).sub.4 (4)

where PEO is a hydrophilic polyethylene-oxide block and PPO is ahydrophobic polypropylene-oxide block. The inclusion of a compatible waxin an amount up to 15% by weight of the total composition and can beeffective to improve guillotinability or cuttability. The presentlypreferred wax is a polyethylene glycol wax, specifically Carbowax™ 1450.

The surfactants may be employed in a concentration of from about 1% toabout 15% by weight of the resin, and preferably have an HLB(hydrophilic-lipophilic balance) value in excess of 7, preferably from12 to greater than 24. To our surprise, addition of these surfactants tohot melt compositions not only improves cutting performance of adhesivelaminates, but also three major advantages over the prior art werefound.

When polyethylene glycol and polysiloxanes are added to adhesivecomposition, adhesive performance goes down considerably, especiallypeel adhesion and tack. Addition of surfactants lower the adhesiveperformance to a significant lesser extent.

Moreover, polysiloxanes and polyethylene glycol are both incompatiblewith rubber-based adhesives. Although they can be used when solventcoating is employed, in hot-melt compositions incompatibility of thesematerials caused a problem due to phase separation.

Due to the hydrophobic nature of the polypropylene-oxide block, thesesurfactants are compatible with rubber-based adhesives and are easy tohandle; phase separation is not a problem. These surfactants cantherefore be utilized for water-based as well as solvent-based adhesivesin addition to use in hot melt adhesives.

The pressure-sensitive adhesive is preferably coated onto asilicone-coated release paper, and any additive added to thepressure-sensitive adhesive (PSA) preferably should not adversely affectthe release characteristics. When the surfactant (Pluronic F-108) wasadded to a hot melt formulation, release characteristics were notaffected greatly at all speed ranges tested (up to 300 m/min). (SeeTable 2 below for description of Pluronic F-108.) Whenpolyethylene-glycol is added to a similar adhesive composition, highspeed release became adversely affected and became harder to release.One of the converting process includes label making process where rotarydie cutting and matrix stripping is quite often the rate determiningprocess. The matrix stripping requires good release characteristics overa wide range of speeds and is especially important at high speeds. Ifthe release is too tight the matrix breaks and converting speed suffers.Even if cutting performance is improved, this may not overcome matrixstripping difficulties. When conversion was tested on a high-speed MarkAndy Press compositions containing polyethylene glycol showedconvertability worse than adhesive without additives, while PluronicF-108 addition increased converting speed markedly.

The elastomeric or rubber-based pressure-sensitive adhesive ispreferably based on a combination of two or more immiscible elastomerswhich, when combined in proper proportion, provide at least two glasstransition temperatures, and by the addition of one or more tackifiers.Addition of one or more of the tackifiers produces an increase in thedifference between the two glass transition temperatures as aconsequence of preferential miscibility of the tackifier in theelastomer having the highest glass transition temperature and anamplification of tangent delta of the elastomer having the higher glasstransition temperature. Although explained in terms of diene elastomers,the invention is contemplated to be applicable to immiscible tackifiableand internally tackified polymers including, but not limited to, acrylicester based polymers and the like.

The surfactant additive may have utility with rubber-based andacrylic-based adhesives having a single glass transition temperature.

In a preferred aspect, the invention is based on an admixture of a firstelastomer providing a first polymerized diene, preferably polybutadiene,and exhibiting a first glass transition temperature and a second naturalor synthetic elastomer providing a second polymerized diene component,preferably polyisoprene, and having a second glass transitiontemperature higher than the first. The elastomers are mixed inproportion to exhibit a dynamic mechanical spectrum (DMS), i.e., a plotof a tangent delta (the ratio of G'' to G' as defined herein) againsttemperature, with at least two, as opposed to one, distinct peakscorresponding to glass transition temperatures of the first polymerizeddiene (polybutadiene) and second polymerized diene (polyisoprene)components of the immiscible blend. A tackifying system comprising atleast one solid tackifier is added to increase the glass transitiontemperature of at least the second peak in order to increase thetemperature differential between the peaks, while increasing theamplitude (tangent delta) of the second (polyisoprene) peak. Shifting atleast the second peak toward ambient temperature improves ambienttemperature pressure-sensitive adhesive performance. The maintenance ofthe first peak assures low temperature pressure-sensitive adhesiveperformance. Low values of tangent delta give good processability andcuttability.

The immiscible rubbers are provided in proportion of the polybutadienecontaining elastomer to the polyisoprene containing elastomer from about0.5:1 to about 5:1 and comprise from about 20% to about 50% by weight ofthe total weight of the mixture of elastomers and tackifying additive.

The tackifying system is preferentially soluble in the polyisoprenecomponent and comprises a normally solid tackifying resin, preferablybased on polymerized structures derived from aliphatic dienes andmono-olefins containing 5 or 6 carbon atoms, preferably with at least40% of the structures derived from piperylene or from piperylene andisoprene, aromatic resins which are hydrogenated to the degree thatsubstantially all of the benzene rings are converted to cyclohexanerings, and hydrogenated polycyclic resins such as hydrogenateddicyclopentadiene resins. The additive system preferably includes anormally liquid tackifying resin which is preferentially soluble in thepolyisoprene component. Other constituents of the tackifying system mayinclude rosin, rosin ester and polyterpenes which are at least partiallycompatible with the polyisoprene component, and plasticizing oils. Theadditives do not, however, limit the function of the tackifiers, namely,increasing the glass transition temperature differential between thepeaks.

Presently preferred compositions are those in which the ratio of thepolybutadiene-based elastomer to the polyisoprene-based elastomer isabout 1.3:1 and present in about 15% to about 30% by weight based on thetotal composition, the balance of the composition, except forinhibitors, antioxidants and other modifiers, are tackifiers.

The invention is also useful in improving cutting performance of naturalrubber (polyisoprene) based adhesives as well as styrene-isoprene andstyrene butadiene di and triblock copolymers.

THE DRAWINGS

FIGS. 1 to 7 are block diagrams illustrating 90° peel in pounds per inchto various substrates of the composition identified in Table 8 and arebased on the date reported in Tables 9 and 10. The face stocks orbacking were satin litho, high gloss paper and primed high gloss paper.In the FIGURE, "p" means panel failure, "ps" means panel stain and "F"means face stock failure.

DETAILED DESCRIPTION

The present invention is directed to improving the cuttability ofelastomeric pressure-sensitive adhesives, especially adhesives based onpolymers of butadiene and isoprene, preferably mixtures of twoimmiscible natural or synthetic elastomers, one based on a firstpolydiene, preferably polybutadiene or one containing polybutadieneblocks, exhibiting a first glass transition temperature and a value oftangent delta and the other based on a second polydiene, preferablypolyisoprene or one containing polyisoprene blocks exhibiting a secondglass transition temperature higher than the first and a second value oftangent delta associated therewith. The two elastomers are combined inproportion whereby there is exhibited two distinct glass transitiontemperature peaks in a DMS curve, a plot of tangent delta as a functionof temperature in ° C. There is provided to the composition a tackifyingsystem which comprises tackifiers preferentially soluble in the secondpolydiene component which cause the temperature differential between theglass transition temperature peaks in the DMS curve to increase and theamplitude of the tangent delta for the second glass transitiontemperature to also increase. The net result is to provide apressure-sensitive adhesive composition exhibiting improved conversionas seen in ability to cut the adhesive and excellent low and ambienttemperature pressure-sensitive adhesive performance. The performance ofthe adhesive is improved even more by additives which also benefitcuttability of tackified styrene-butadiene-styrene, styrene-butadiene,styrene-isoprene-styrene, styrene-isoprene and like copolymers as wellas natural rubbers (polyisoprene) and other related elastomer polymers.The additives may be used in solvent, emulsion and hot-melt adhesives.Hot melt adhesives are especially benefitted. The preferred adhesivessystems are described in detail in U.S. patent application Ser. No.07/755,585 filed Sep. 3, 1991, and incorporated herein by reference.

As used for such adhesive, "tackifier system" consists of tackifiersinclude normally liquid and solid tackifiers which leave unchanged theglass transition temperature of the elastomeric block in which they arenot soluble. There may also be employed plasticizer oils which lower theglass transition temperature. Tackifier systems used in the practice ofthe instant invention, include conventional tackifiers and plasticizeroils, and for the preferred blends of incompatible elastomers have thenet effect of being preferentially soluble in the polyisoprene block soas to preferentially increase the difference between the glasstransition temperature of the polyisoprene block component relative tothe polybutadiene block component, with an increase (amplification) ofthe tangent delta of the polyisoprene peaks of the pressure-sensitiveadhesive composition.

More particularly, polymers used in formulating the pressure-sensitiveadhesives of this invention are based on natural and/or syntheticelastomeric polymers. Useful are AB, ABA and (AB)_(x) block copolymerswherein x has a value of 3 or more and wherein A is a block comprisingat least one monoalkenyl arene, preferably styrene, alpha methylstyrene, vinyl toluene and the like, and B is an elastomeric conjugateddiene block, preferably a polybutadiene or a polyisoprene block.Preferably at least one is based on polybutadiene blocks and one otheris based on polyisoprene blocks. These include, but are not limited to,homopolymers, block, random or multiarmed copolymers, and mixturesthereof. Among the useful elastomeric polymers there may be mentionednatural rubber (polyisoprene), polybutadiene, synthetic polyisoprene,random styrene-butadiene polymers, styrene-butadiene (SB) blockcopolymers, multiarmed and repeating (SB) copolymers,styrene-butadiene-styrene (SBS) block copolymers, styrene-isoprene (SI)block copolymers, styrene-isoprene-styrene (SIS) block copolymers,multiarmed styrene-isoprene (SI)_(x) block copolymers, and the like. Itwill be understood that random copolymers may also be used and canreverse the diene preferentially tackified so long as the glasstransition temperature of the polymer exhibiting the highest glasstransition temperature is increased relative to the polymer of lowerglass transition temperature.

Commercial elastomeric polymers used include linear SIS/SI blockcopolymers known as Kraton D-1107 and D-1112, SBS/SB block copolymersknown as Kraton D-1101, D-1102 and DX-1300, and an (SI), block copolymerknown as Kraton D-1320X, all manufactured and sold by Shell ChemicalCompany, and an SB block copolymer known as Solprene 1205 manufacturedand sold by Housemex, Inc. As indicated, in many of the SIS or SBS blockcopolymers, there are respectively present SI or SB components.

Other elastomers, such as the ethylene-propylene diene rubbers,styrene-ethylene/butylene, styrene block copolymers,styrene-ethylene/propylene-styrene block copolymers and the like, mayalso be used.

The weight ratio of the polybutadiene containing constituents of themixture to the polyisoprene constituents of the mixture are such thatthere are provided two peaks on the DMS curve for the mixture.Generally, weight ratios range from about 0.5:1 upward. Compositionscontemplated to be used in accordance with the instant invention arecombined in ratio of about 0.5:1 to about 5:1, preferably from about 1:1to about 1.5:1, and most preferably from about 1.3:1.

Tackifier additives for the polyisoprene component are preferablyobtained by the polymerization of a stream of aliphatic petroleumderivatives in the form of dienes and mono-olefins containing 5 or 6carbon atoms generally in accordance with the teachings of U.S. Pat.Nos. 3,577,398 to Pace and 3,692,756 to St. Cyr, both incorporatedherein by reference. The resultant hydrocarbons range from materialswhich are normally liquid at room temperature to those which arenormally solid at room temperature and typically contain 40% or more byweight polymerized dienes. The dienes are typically piperylene and/orisoprene. They are sold by the Chemical Division of Goodyear Tire andRubber Company as the Wingtack family of resins with the numericaldesignation being the softening point, e.g., Wingtack 95 which isnormally a solid resin having a softening point of about 95° C. andWingtack 10 which is normally a liquid resin having a softening point ofabout 10° C.

Other normally solid tackifiers are Escorez 1310 LC manufactured byExxon and Piccotac 95 manufactured by Hercules.

Other additives which may serve a tackifier function includehydrogenated aromatic resins wherein a very substantial portion, if notall, of the benzene rings are converted to cyclohexane rings (forexample, the Regalrez family of resins manufactured by Hercules such asRegalrez 1018, 1033, 1065, 1078 and 1126, and Regalite R-100, and theArkon family of resins from Arakwa Chemical such as Arkon p-85, p-100,p-115 and P-125), hydrogenated polycyclic resins (typicallydicyclopentadiene resins such as Escorez 5300, 5320, 5340 and 5380manufactured by Exxon) and the like.

There can be also added rosins, rosin esters, polyterpenes and othertackifiers which are compatible to some degree with the polyisoprene andpolybutadiene phases. Other additives include plasticizer oils such asShellflex 371 manufactured by Shell and Kaydol mineral oil manufacturedby Witco which are soluble in both the polyisoprene and polybutadienephases.

The tackifier system may be present in an amount, based on the totalweight of tackifier system and elastomers, of from about 50% to about80% by weight, preferably from about 50% to about 70% by weight, morepreferably from about 60% to about 70% by weight. The presentlypreferred ratio is about 38% by weight elastomer and about 62% by weighttackifying resin additive, the resin additive preferably being a mixtureof a normally solid tackifier such as Wingtack 95 or Escorez 1310 LC anda normally liquid tackifier such as Wingtack 10 or a plasticizer oilsuch as Shellflex 371. Polystyrene reinforcing additives may be presentbut are not required.

The surfactants employed to improve cuttability of the above-mentionedadhesive systems are block copolymer surfactants preferably havinghydrophilic polyethylene-oxide (PEO) blocks and hydrophobicpolypropylene-oxide (PPO) blocks and are generally of the formula:##STR1## Mixtures may also be used. Surfactants of formulas (1) and (2)above are Pluronic™ surfactants, and surfactants of formulas (3) and (4)above are known as the Tetronic surfactants. Both are made by BASF. Thepresently preferred surfactant is Pluronic F-108 which has a molecularweight of 14600 and an HLB of greater than 24.

The surfactant may be employed in concentration of from about 1% toabout 6% by weight of surfactant and elastomer, preferably from about 2%to about 5% by weight, with optimized concentration varying depending onthe nature of the surfactant and/or the adhesive polymer. The HLB valueshould exceed 7, and preferably at least 12, and most preferably atleast 24.

The surfactant may be augmented by the addition of 0 to 15% by weight ofthe total composition of a wax including natural waxes such as montanwax, carnauba wax, bees wax and the like, synthetic waxes such aspolyethylene and polypropylene waxes, Fischer-Tropsch waxes,microcrystalline waxes and the like. It is presently preferred to employpolyethylene glycol waxes, preferably Carbowax™ 1450.

While, as will be seen, the pressure-sensitive adhesive formulations ofthe instant invention exhibit excellent low temperature and ambienttemperature performance as well as convertability, it may be desirableto enhance elevated temperature performance. This may be accomplished bycross-linking techniques such as the use of electron beam (EB) radiationor ultraviolet (UV) radiation or chemical cross-linking or a combinationof these. If employed, it is desirable that tackifying additives besubstantially saturated such that all of the energy of cure goes intocross-linking of the elastomeric components of the adhesive.

The following adhesive composition is the presently preferred hot meltadhesive as used to evaluate various surfactants identified in thetables to follow, and is the control when used with no surfactantadditive:

    ______________________________________                                        Elastomer and tackifier system:                                               Solprene 1205        21.2%                                                    Kraton 1107          16.8%                                                    Escorez 1310 LC      24.0%                                                    Wingtack 10          38.0%                                                    Antioxidants:                                                                 Ethyl 330            0.7 pph                                                  Cyanox LTDP          0.7 pph                                                  ______________________________________                                    

In the following tables a blade rating lower than 3 is regarded asrepresenting an improvement in cuttability, with 3 being the bladerating for the adhesive alone. A blade rating of 3 or greater representscuttability that was not improved.

In the Following Tables:

"BCS" means block copolymer surfactant

"pph" means parts by weight per 100 parts adhesive

"N/m" means Newtons per meter

"RT" means room temperature

"QS" means quick stick

"PE" means polyethylene

"CB" means recycled cardboard

"GL" means glass

"SS" means stainless steel

"HR" means hour

"DW" means dwell

"SL" means slight

The following tables describe experiments which illustrate the benefitsof the addition of block copolymer surfactants to pressure-sensitiveadhesives:

                                      TABLE 1                                     __________________________________________________________________________    GUILLOTINE PERFORMANCE TESTING OF TETRONIC R BLOCK COPOLYMER SURFACTANTS             VISCOS-                    GUILLOTINE                                         ITY @ BCS                  PERFORMANCE TEST     STRINGI-               TEST   175° C.                                                                      AVE HYDROPHILE %     BLADE        FACESTOCK                                                                             NESS/                  SAMPLE Pa.s  MW  POLYOXYETHYLENE                                                                            HLB RATING*                                                                             STACK  ANCHORAGE                                                                             LEGGINESS              __________________________________________________________________________    CONTROL                                                                              14.6  --  --           --  3     SL.    OK      SHORT                                                          CLUMPING                              TETRONIC                                                                      R BCS                                                                         3 pph  19.4  18700                                                                             80           12-18                                                                             3.5   SL.    OK      MEDIUM                                                         CLUMPING                              3 pph  19.9  10200                                                                             80           12-18                                                                             2.8   SL.    OK      MEDIUM                                                         CLUMPING                              3 pph  17.4  7240                                                                              40           1-7 3.3   SL.    VERY POOR                                                                             LONG                                                           CLUMPING                              3 pph  17.9  5230                                                                              40            7-12                                                                             2.8   SL.    VERY POOR                                                                             LONG                                                           CLUMPING                              3 pph  16.6  3740                                                                              40            7-12                                                                             3     SL.    VERY POOR                                                                             LONG                                                           CLUMPING                              __________________________________________________________________________     *BLADE RATING                                                                 1  Excellent                                                                  2  Very Good                                                                  3  Good                                                                       4  Fair                                                                       5  Poor                                                                       6  Very Poor                                                                  Adhesive on Guillotine Blade Description                                      No adhesive on blade                                                          Adhesive only on the very edge of blade. None on the sides.                   Adhesive beginning to stick to the sides of the blade (approximately 1/8"     Adhesive beginning to stick to the sides of the blade (approximately 1/4"     Adhesive approximately 1/2" on the blade                                      Adhesive building higher and/or thicker with each cut.                   

                                      TABLE 2                                     __________________________________________________________________________    PERFORMANCE OF PLURONIC SURFACTANTS                                                  VISCOS-                    GUILLOTINE                                         ITY @ BCS                  PERFORMANCE TEST     STRINGI-               TEST   175° C.                                                                      AVE HYDROPHILE %     BLADE        FACESTOCK                                                                             NESS/                  SAMPLE Pa.s  MW  POLYOXYETHYLENE                                                                            HLB RATING*                                                                             STACK  ANCHORAGE                                                                             LEGGINESS              __________________________________________________________________________    (0 pph)                                                                              14.6  --  --           --  3     SL.    OK      SHORT                  CONTROL                                 CLUMPING                              BCS ADD-                                                                      ITIVES                                                                        PLURONIC     14600                                                                             80           >24                                             F-108                                                                         3 pph  12.4                       3     V. SL. OK      LONG                                                           CLUMPING                              4 pph  13.6                       2.2   NO     OK      LONG                                                           CLUMPING                              5 pph  13.8                       1.5   NO     OK      LONG                                                           CLUMPING                              PLURONIC      7000                                                                             80           12-18                                           R 17R8                                                                        3 pph  18                         2     NO     OK      LONG                                                           CLUMPING                              4 pph  19                         2.5   V. SL. OK      LONG                                                           CLUMPING                              5 pph  19.5                       1.5   V. SL. OK      LONG                                                           CLUMPING                              TETRONIC     25000                                                                             80           >24                                             908                                                                           3 pph  18.7                       2.5   NO     OK      LONG                                                           CLUMPING                              4 pph  15.4                       2.5   NO     OK      MEDIUM                                                         CLUMPING                              5 pph  19.2                       2.3   V. SL. OK      LONG                                                           CLUMPING                              TETRONIC     10200                                                                             80           12-18                                           R 50R8                                                                        3 pph  17.7                       3     V. SL. OK      LONG                                                           CLUMPING                              4 pph  19.4                       2.7   NO     OK      LONG                                                           CLUMPING                              5 pph  19.8                       1.5   NO     OK      LONG                                                           CLUMPING                              __________________________________________________________________________

                                      TABLE 3                                     __________________________________________________________________________    GUILLOTINE PERFORMANCE TESTING OF BLOCK COPOLYMER SURFACTANTS AT 5 PPH        LEVELS                                                                               VISCOS-                    GUILLOTINE                                         ITY @ BCS                  PERFORMANCE TEST     STRINGI-               TEST   175° C.                                                                      AVE HYDROPHILE %     BLADE        FACESTOCK                                                                             NESS/                  SAMPLE Pa.s  MW  POLYOXYETHYLENE                                                                            HLB RATING*                                                                             STACK  ANCHORAGE                                                                             LEGGINESS              __________________________________________________________________________    BCS (5 pph)                                                                   Tetronic                                                                             19.3  25000                                                                             80           >24 2     NO     OK      SHORT                  908                                     CLUMPING                              Pluronic                                                                             18.1   2650                                                                             40           7-12                                                                              2     NO     OK      MEDIUM                 17R4                                    CLUMPING                              Pluronic                                                                             16.3  14600                                                                             80           >24 1     NO     VERY POOR                                                                             LONG                   F108                                    CLUMPING                              __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________    GUILLOTINE PERFORMANCE TESTING OF TETRONIC R BLOCK COPOLYMER SURFACTANTS             VISCOS-                    GUILLOTINE                                         ITY @ BCS                  PERFORMANCE TEST     STRINGI-               TEST   175° C.                                                                      AVE HYDROPHILE %     BLADE        FACESTOCK                                                                             NESS/                  SAMPLE Pa.s  MW  POLYOXYETHYLENE                                                                            HLB RATING*                                                                             STACK  ANCHORAGE                                                                             LEGGINESS              __________________________________________________________________________    TETRONIC                                                                      R BCS                                                                         3 pph 90R8                                                                           19.4  18700                                                                             80           12-18                                                                             3.5   SL.    OK      MEDIUM                                                         CLUMPING                              3 pph 50R8                                                                           19.9  10200                                                                             80           12-18                                                                             2.8   SL.    OK      MEDIUM                                                         CLUMPING                              3 pph 90R4                                                                           17.4  7240                                                                              40           1-7 3.3   SL.    VERY POOR                                                                             LONG                                                           CLUMPING                              3 pph 70R4                                                                           17.9  5230                                                                              40            7-12                                                                             2.8   SL.    VERY POOR                                                                             LONG                                                           CLUMPING                              3 pph 50R4                                                                           16.6  3740                                                                              40            7-12                                                                             3     SL.    VERY POOR                                                                             LONG                                                           CLUMPING                              __________________________________________________________________________

                                      TABLE 5                                     __________________________________________________________________________    GUILLOTINE PERFORMANCE TESTING OF PLURONIC BLOCK COPOLYMER SURFACTANTS               VISCOS-                    GUILLOTINE                                         ITY @ BCS                  PERFORMANCE TEST     STRINGI-               TEST   175° C.                                                                      AVE HYDROPHILE %     BLADE        FACESTOCK                                                                             NESS/                  SAMPLE Pa.s  MW  POLYOXYETHYLENE                                                                            HLB RATING*                                                                             STACK  ANCHORAGE                                                                             LEGGINESS              __________________________________________________________________________    PLURONIC                                                                      BCS                                                                           3 pph F108                                                                           16.8  14600                                                                             80           >24 2.5   NO     OK      SHORT                                                          CLUMPING                              3 pph F-88                                                                           13.6  11400                                                                             80           >24 2.8   NO     OK      SHORT                                                          CLUMPING                              3 pph F-87                                                                           18    7700                                                                              70           >24 2.5   CLUMPING                                                                             POOR    LONG                   3 pph P-85                                                                           19    4600                                                                              50           12-18                                                                             3.5   CLUMPING                                                                             VERY POOR                                                                             LONG                   3 pph F-68                                                                           13    8400                                                                              80           >24 2.5   NO     OK      SHORT                                                          CLUMPING                              __________________________________________________________________________

                                      TABLE 6                                     __________________________________________________________________________    GUILLOTINE PERFORMANCE TESTING OF PLURONIC R BLOCK COPOLYMER SURFACTANTS             VISCOS-                    GUILLOTINE                                         ITY @ BCS                  PERFORMANCE TEST     STRINGI-               TEST   175° C.                                                                      AVE HYDROPHILE %     BLADE        FACESTOCK                                                                             NESS/                  SAMPLE Pa.s  MW  POLYOXYETHYLENE                                                                            HLB RATING*                                                                             STACK  ANCHORAGE                                                                             LEGGINESS              __________________________________________________________________________    PLURONIC                                                                      R BCS                                                                         3 pph 25R-8                                                                          15.7  8550                                                                              80           12-18                                                                             2.6   NO     OK      LONG                                                           CLUMPING                              3 pph 17R-8                                                                          13.6  7000                                                                              80           12-18                                                                             2.2   NO     OK      SHORT-                                                         CLUMPING       MEDIUM                 3 pph 10R-8                                                                          18.8  4550                                                                              80           18-23                                                                             3     V. V. SL.                                                                            OK      LONG                                                           CLUMPING                              3 pph 25R-5                                                                          18.7  4250                                                                              50            7-12                                                                             3     NO     VERY POOR                                                                             LONG                                                           CLUMPING                              3 pph 10R-5                                                                          15.5  1950                                                                              50           12-18                                                                             2.4   V. V. SL.                                                                            VERY POOR                                                                             LONG                                                           CLUMPING                              __________________________________________________________________________

                                      TABLE 7                                     __________________________________________________________________________    GUILLOTINE PERFORMANCE TESTING OF TETRONIC BLOCK COPOLYMER SURFACTANTS               VISCOS-                    GUILLOTINE                                         ITY @ BCS                  PERFORMANCE TEST     STRINGI-               TEST   175° C.                                                                      AVE HYDROPHILE %     BLADE        FACESTOCK                                                                             NESS/                  SAMPLE Pa.s  MW  POLYOXYETHYLENE                                                                            HLB RATING*                                                                             STACK  ANCHORAGE                                                                             LEGGINESS              __________________________________________________________________________    TETRONIC                                                                      BCS                                                                           3 pph 707                                                                            16.7  12200                                                                             70           >24 2.8   NO     OK      SHORT                                                          CLUMPING                              3 pph 1107                                                                           19.9  15000                                                                             70           18-23                                                                             3     V. SL. OK      SHORT                                                          CLUMPING                              3 pph 1307                                                                           17.8  18000                                                                             70           18-23                                                                             3     SL.    OK      MEDIUM                                                         CLUMPING                              3 pph 1508                                                                           18.1  30000                                                                             80           >24 3.5   CLUMPING                                                                             OK      MEDIUM                                                         CLUMPING                              3 pph 901                                                                            15.5   4700                                                                             10            1-7                                                                              3.5   CLUMPING                                                                             VERY POOR                                                                             LONG                   3 pph 904                                                                            16.8   6700                                                                             40           12-18                                                                             3     SL.    VERY POOR                                                                             LONG                                                           CLUMPING                              3 pph 908                                                                            18.7  25000                                                                             80           >24 3     SL.    OK      SHORT                                                          CLUMPING                              __________________________________________________________________________

Tables 8, 9 and 10:

Table 8 shows compositions based on the addition of Carbowax™ 1450 tocompositions of the invention while Tables 9 and 10 report the adhesiveperformance of such compositions, some to a control which was asolvent-based removable adhesive based on butyl rubber which had aguillotine value of 0.1875 Composition B(2) is a repeat of CompositionB.

                  TABLE 8                                                         ______________________________________                                                  Composition                                                                            Composition                                                                              Composition                                               A        B + B(2)   C                                                         PPH      PPH        PPH                                             ______________________________________                                        KRATON RP 6403                                                                            34         42         --                                          (SIS/SI)                                                                      DPX 512     --         --         18                                          (100% SIS)                                                                    SOLPRENE 1205                                                                             --         --         24                                          (SB)                                                                          ECR 143 (Tackifier)                                                                       50         41         41                                          PLURONIC F108                                                                             11          5         12                                          (Surfactant)                                                                  CARBOWAX 1450                                                                              5         12          5                                          (Wax)                                                                         CAMEL WITE   5          5          5                                          (Opacifier)                                                                   IRGANOX 565  0.3        0.3        0.3                                        (antioxidant)                                                                 IRGAFOS 168  0.6        0.6        0.6                                        (antioxidant)                                                                 (GUILLOTINE)                                                                               0.1875     0.1875     0.25                                       BLADE SMEAR             0.1875 (2)                                            HT. (inches)                                                                  ______________________________________                                    

                  TABLE 9                                                         ______________________________________                                                                              Appli-                                                                        ance                                    S.S.         ABS      HDPE     Glass  Enamel                                  ______________________________________                                        1 Day/                                                                        25° C.                                                                 Composi-                                                                              1.07,p   1.63,p   0.82,p 0.82,p 0.889,p                               tion A                                                                        Composi-                                                                              0.992,p  1.44,p   0.81,p 0.81,p 0.77,p                                tion B                                                                        Composi-                                                                              0.906,p  1.15,p1  0.69,p 0.70,p1                                                                              0.85,p                                tion (B)2                                                                     Composi-                                                                              1.005,p1 1.43,p1  0.88,p 1.12,p1                                                                              0.883,p1                              tion C                                                                        Control 0.426,p  0.639,p1 0.398,p                                                                              0.528,p                                                                              0.41,p                                7 Day/                                                                        25° C.                                                                 Composi-                                                                              1.21,p   1.99,pt  0.842,p                                                                              0.956,p                                                                              0.90,p                                tion A                                                                        Composi-                                                                              1.15,p   1.59,p1  0.86,p 0.97,p 0.88,p                                tion B                                                                        Composi-                                                                              0.922,p  1.32,pt  0.59,p 0.881,p1                                                                             0.942,p                               tion C                                                                        Composi-                                                                              1.097,p1 1.74,p1  0.82,p 1.033,p1                                                                             0.925,p1                              tion D                                                                        Control 0.71,p   0.84,p1  0.558,p                                                                              0.846,p                                                                              0.718,p                               14 Day/                                                                       25° C.                                                                 Composi-                                                                              1.272,p  2.327,p2 0.915,p                                                                              0.98,p 0.97,p                                tion A                                                                        Composi-                                                                              1.174,p  1.49,p1  0.86,p 0.96,p 0.95,p                                tion B                                                                        Composi-                                                                              0.957,p  1.44,pt  0.68,p 1.0,p  1.10,p                                tion C                                                                        Composi-                                                                              1.11,p1  1.71,pt  0.913,p                                                                              1.04,p1                                                                              0.87,p1                               tion D                                                                        Control 0.85,p   0.90,p1  0.7,p  0.917,p                                                                              0.822,p                               ______________________________________                                         Facestock: 01124/P-32                                                         Coat Weight: 21 ± gsm                                                      p1: very light shade                                                          p2: light staining                                                            p3: heavy staining                                                            pt: paper tore                                                           

                  TABLE 10                                                        ______________________________________                                                                              Appli-                                                                        ance                                    S.S.         ABS      HDPE     Glass  Enamel                                  ______________________________________                                        1 Day/                                                                        50° C.                                                                 Composi-                                                                              1.05,p1  2.16,F   0.89,p 0.87,p1                                                                              0.93,p                                tion A                                                                        Composi-                                                                              1.03,p1  2.34,F   0.933,p                                                                              0.95,p1                                                                              0.81,p1                               tion B                                                                        Composi-                                                                              0.85,p1  1.69,p2  0.78,p 0.89,p1                                                                              0.65,p1                               tion C                                                                        Composi-                                                                              1.13,p2  2.20,p3  0.912,p                                                                              0.91,p1                                                                              0.99,p1                               tion D                                                                        Control 0.845,p1 0.89,p2  0.77,p1                                                                              0.941,p                                                                              0.81,p                                14 Day/                                                                       50° C.                                                                 Composi-                                                                              1.09,p1  2.049,p3 0.84,p 0.96,p1                                                                              1.101,p                               tion A                                                                        Composi-                                                                              1.19,p1  1.893,F  0.904,p                                                                              1.02,p1                                                                              1.207,p1                              tion B                                                                        Composi-                                                                              1.81,pt  1.625,p3 0.77,p1                                                                              1.16,p1                                                                              1.10,p2                               tion C                                                                        Composi-                                                                              1.102,p2 2.27,p3  0.90,p 1.02,p1                                                                              1.06,p1                               tion D                                                                        Control 0.894,p  1.01,p2  1.10,p1                                                                              0.911,p                                                                              0.791,p                               28 Day/                                                                       50° C.                                                                 Composi-                                                                              1.81,p3  1.125,p3 tore   2.0,p3 0.82,p3                               tion A                                                                        Composi-                                                                              0.82,p3  1.55,p3  1.23,p3                                                                              1.08,p3                                                                              1.13,p3                               tion B                                                                        Composi-                                                                              1.44,p3  NA       0.75,p2                                                                              1.11,p3                                                                              1.38,p3                               tion C                                                                        Composi-                                                                              1.55,p3  1.73,pt  1.363,pt                                                                             1.42,p3                                                                              1.27,p3                               tion D                                                                        Control 1.03,p   1.33,p2  2.14,pt                                                                              1.11,p 1.048,p                               ______________________________________                                         Facestock: 01124/P-32                                                         Coat Weight: 21 ± gsm                                                      p1: very light shade                                                          p2: light staining                                                            p3: heavy staining                                                            pt: paper tore                                                           

What is claimed is:
 1. A pressure-sensitive adhesive exhibiting improvedcuttability of a pressure-sensitive label construction which comprisesan elastomeric hot melt pressure-sensitive adhesive containing fromabout 1 to about 15%, by weight, based on the weight of surfactant andelastomer pressure-sensitive adhesive of a surfactant comprised ofhydrophilic polyethylene-oxide blocks and hydrophobicpolyproplyene-oxide blocks, and having an HLB value greater than 7 andfrom 0 to about 15% by weight of the composition of a compatible waxsaid elastomeric portion of the elastomeric pressure-sensitive adhesivecomprising of:i. a first elastomer selected from the group consisting ofa styrene-butadiene block copolymer, a styrene-butadiene-styrene blockcopolymer and mixtures thereof, said first elastomer exhibiting a firstglass transition temperature and a first value of tangent delta measuredas a function of temperature; ii. a second elastomer selected from thegroup consisting of styrene-isoprene-styrene block copolymers,styrene-isoprene block copolymers, multiarmed styrene-isoprene blockcopolymers and mixtures thereof, said second elastomer exhibiting asecond glass transition temperature greater than the first glasstransition temperature and a second value of tangent delta measured asfunction of temperature, the second elastomer being immiscible in thefirst elastomer, said first and second elastomers provided inproportions of 0.5:1 to 5:1 and in which a DMS plot of tangent delta asa function of temperature exhibits a polybutadiene-attributable firstglass transition temperature peak determinable separate from and lowerthan polyisoprene-attributable second glass transition temperature peak;and iii. a tackifying system comprising a normally solid tackifyingcomponent having a softening point of about 95° C. and obtained bypolymerization of a stream solely composed of aliphatic petroleumderivatives in the form of dienes and monoolefins containing 5 or 6carbon atoms, said tackifying component being preferentially misciblewith the polyisoprene blocks of the second elastomer and present in anamount of from about 50 percent to about 80 percent by weight of theelastomers and tackifying system and sufficient to cause an increase inthe second glass transition temperature and an increase in thetemperature difference between the polybutadiene-attributable glasstransition temperature peak and the polyisoprene-attributable glasstransition temperature peak and an increase in the tangent delta valueattributed to the polyisoprene-attributable peak.
 2. Apressure-sensitive adhesive as claimed in claim 1 in which thesurfactant is selected from the group consisting of compounds of theformula: ##STR2## and mixtures thereof wherein PEO means apolyethylene-oxide block and PPO means a polypropylene-oxide block.
 3. Apressure-sensitive adhesive as claimed in claim 1 in which thesurfactant is present in an amount of from about 1 to about 6% by weightof the surfactant and elastomeric pressure-sensitive adhesive.
 4. Apressure-sensitive adhesive as claimed in claim 2 in which thesurfactant is present in an amount of from about 1 to about 6% by weightof the surfactant and elastomeric pressure-sensitive adhesive.
 5. Apressure-sensitive adhesive as claimed in claim 1 in which the wax is apolyethylene glycol wax.
 6. A pressure-sensitive adhesive as claimed inclaim 2 in which the wax is a polyethylene glycol wax.
 7. Apressure-sensitive adhesive as claimed in claim 1 in which the weightratio of the first elastomer to the second elastomer is about 0.5:1 toabout 1:1.
 8. A pressure-sensitive adhesive as claimed in claim 1 inwhich the weight ratio of the first elastomer to the second elastomer isat about 1.0:1 to about 1.5:1.
 9. A pressure-sensitive adhesive asclaimed in claim 1 in which the weight ratio of the first elastomer tothe second elastomer is about 1.0:1 to about 1.5:1.
 10. Apressure-sensitive adhesive as claimed in claim 1 in which a first andsecond elastomer are present in an amount of from about 30% to about 50%by weight based on the total weight of the mixture and tackifyingsystem.
 11. A pressure-sensitive label construction having a layer ofadhesive according to claim 1 and sufficient to improve guillotinabilityof the resultant label construction.
 12. A pressure-sensitive labelconstruction having a layer of adhesive according to claim 2 andsufficient to improve guillotinability of the resultant labelconstruction.
 13. A pressure sensitive adhesive as claimed in claim 1 inwhich the first tackifying system further comprises a compound selectedfrom the group consisting of a normally liquid tackifying resinsobtained by the polymerization of a stream of aliphatic petroleumderivatives in the form of dienes and monoolefins containing 5 or 6carbon atoms, a plasticizing oil and mixtures thereof.
 14. A pressuresensitive adhesive as claimed in claim 2 in which the tackifying systemfurther comprises a compound selected from the group consisting of anormally liquid tackifying resins obtained by the polymerization of astream of aliphatic petroleum derivatives in the form of dienes andmonoolefins containing 5 or 6 carbon atoms, a plasticizing oil andmixtures thereof.
 15. A pressure-sensitive adhesive as claimed in claim1 in which the weight ratio of the first elastomer to the secondelastomer is about 1.3:1.
 16. A pressure-sensitive adhesive as claimedin claim 1 in which the weight ratio of the first elastomer to thesecond elastomer is about 0.5:1 to about 2.5:1.
 17. A pressure-sensitiveadhesive as claimed in claim 2 in which the weight ratio of the firstelastomer to the second elastomer is about 0.5:1 to about 1.5:1.
 18. Apressure-sensitive adhesive as claimed in claim 13 in which the weightratio of the first elastomer to the second elastomer is about 1:1 toabout 1.5:1.
 19. A pressure-sensitive adhesive as claimed in claim 14 inwhich the weight ratio of the first elastomer to the second elastomer isabout 0.5:1 to about 1.5:1.
 20. A pressure-sensitive adhesive as claimedin claim 13 in which the weight ratio of the first elastomer to thesecond elastomer is about 1.3:1.
 21. A pressure-sensitive adhesive asclaimed in claim 13 in which the weight ratio of the first elastomer tothe second elastomer is about 0.5:1 to about 2.5:1.
 22. Apressure-sensitive adhesive as claimed in claim 14 in which the weightratio of the first elastomer to the second elastomer is about 0.5:1 toabout 2.5:1.
 23. A pressure-sensitive adhesive as claimed in claim 14 inwhich the weight ratio of the first elastomer to the second elastomer isabout 1.3:1.
 24. A pressure-sensitive adhesive as claimed in claim 1 inwhich tackifying system further comprises a tackifier selected from thegroup consisting of rosins, rosin esters and polyterpenes.
 25. Apressure-sensitive adhesive as claimed in claim 2 in which tackifyingsystem further comprises a tackifier selected from the group consistingof rosins, rosin esters and polyterpenes.
 26. A pressure-sensitiveadhesive as claimed in claim 13 in which tackifying system furthercomprises a tackifier selected from the group consisting of rosins,rosin esters and polyterpenes.
 27. A pressure-sensitive adhesive asclaimed in claim 14 in which tackifying system further comprises atackifier selected from the group consisting of rosins, rosin esters andpolyterpenes.